Pedestrian simulation using Viswalk

Name: Middela Mounisai Siddartha Roll No: 141717

3. PEDESTRIAN SIMULATION USING VISWALK 3.1 Aim: To simulate the pedestrian traffic realistically and analyze walking behavior. 3.2 Back ground

VISWALK was developed by PTV vision, a worldwide leading software suite for transportation planning and operations analyses. PTV Vision provides a full range of solutions – including VISUM, VISSIM, VISWALK and further complementary modules. The software suite offers a high level of integration within the overall transportation planning process and, in particular, between strategic planning, transport operations and traffic engineering for macro-, meso- and microscopic application levels. Viswalk is developed in order to allow for simulations with a realistic behavior in pedestrians as well as the possibility to simulate complex situations. This can be done both in interaction with traffic (in combination with Vissim) and without (PTV Group, 2011). The most prevalent mode of transport was and remains walking. But unlike vehicles, pedestrians are individuals and do not follow strict rules. They spontaneously stop, change directions or make sudden turns. VISWALK realistically simulates and analyses walking behavior as no other software. It is suitable for all those, who take the needs of pedestrians into account in their projects or studies, i.e. transport planners and consultants, architects and operators of large buildings and large public spaces, event managers or fire prevention officers. Pedestrian behavior in Viswalk is based on what is known as the Social Force Model. This model takes the somewhat irrational behavior of pedestrians into account. According to Helbing and Molnár (1995), the motion of pedestrians can be considered as a result of human beings being subjected to forces. These forces consist of several internal motivations that together allows for the individual to move in a certain way or direction. The force, F, that causes pedestrians to decelerate or accelerate consists of four terms: F = F driving driving + F social social + F wall wall + F noise noise Where, F driving driving: Driving force in the desired direction

Transportation Division NIT Warangal

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Name: Middela Mounisai Siddartha Roll No: 141717 F social: Forces between pedestrians F wall: Forces from walls F noise: A random force term that is implemented in order to prevent deadlocks at

bottlenecks. Most likely, the most significant motivation for a pedestrian to move is his or her desire to reach a certain destination as soon and as comfortable as possible. However, there are some factors that influence the pedestrian’s path and speed towards reaching the destination. Keeping the distance to obstacles, buildings or objects, and not to forget other pedestrians, is one important factor. Another is possible attractive effects of the motion, such as seeing a friend or a window display, which can make the pedestrian slow down momentarily or even stop or take a detour. All these factors are essential in the Social Force Model. A visualization of the model can be seen in Figure.

Fig 1. Figure visualizing important attributes of the Social Force Model

Due to the internal motivations and forces, pedestrians are automatically forming selforganizing lanes of people walking in the same direction when encountering an opposing flow (Laufer, 2008). A visualization of this can be seen in Fig 2. At narrow passages, the walking direction will change in oscillatory patterns. As a result of this, Viswalk allows for a realistic modeling of the pedestrian walking behavior. Transportation Division NIT Warangal

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Fig 2. Figure showing self-organized lanes of pedestrians in a narrow pa ssage. Black/white

pedestrians are walking in one direction and grey pedestrians in the other (PTV Group, 2010). VISSIM, the traffic simulation solution from the PTV Vision software suite, started “on the street”. For analysis and simulation of complex traffic situations, it has been used around the world for many years. Whether you implement urban design plans or plan intersection or junction sequences – with VISSIM you model your influence on traffic flow in the simulation. Furthermore you are able to measure the impact of traffic and traffic signal control on the respective waiting times. VISWALK and VISSIM is the fully integrated package from PTV that allows you to simulate the interaction of pedestrians and road traffic. 3.3 PTV Viswalk Functions 3.3.1 Graphical editor (GUI) that allows users to work with the following elements:

1. Areas as walkable space for pedestrians (rectangles, any polygons) 2. Obstacles blocking the walkable areas to pedestrians (rectangles, as polygons) 3. CAD import (DWG files) for areas and obstacles 4. Option of integrating additional formats as a background image (JPG, PNG, BMP, DXF, DWG, SHP and others) 5. Routes predefining the pedestrians' walk from area to area 6. Routing decisions where the pedestrians chooses a rou te from the set of routes


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Name: Middela Mounisai Siddartha Roll No: 141717 7. Inputs that define by time interval how many pedestrians will enter the simulation at which time 8. Alternative option to the inputs/routes concept: definition of demand and routes using origindestination matrices (interval-dependent) 9. Access to the model parameters (Social Force Model), including desired speed 10. Desired speed distributions which can be entered and changed according to user preferences 11. Unlimited number of levels (storeys) 12. Ramps and stairs connecting levels 13. Escalators (and moving walkways) connecting two levels 14. Moving walkways which - similar to escalators, but without a difference in height - also move standing pedestrians 15. 2D view and 3D view are already provided during the simulation and model creation. Users can toggle between the two views 16. LOS display 17. AVI recording of animation - results export to 3D Studio Max PTV Viswalk and replay in PTV Viswalk 18. Flexible design options for areas, obstacles and pedestrian models 19. Possibility of assigning individual areas different walking behaviours (speed distribution and parameters) 3.3.2 Measurement areas

1. Measurement of various parameters of individual pe destrians (e.g. time spent at measurement area, average speed, etc.)Time-aggregated measurements 2. Journey time and distance measurement: "from area A to area B" 3. Queuing data and -analysis (time-aggregated) 4. Congestion identification 5. Partial routes for local redistribution in line with the implicitly or explicitly defined origindestination matrix 6. Dynamic potential: calculation of the desired direction based on the estimated remaining journey time (in contrast to the calculation of the desired direction based on the shortest distance). "One-shot assignment" Transportation Division NIT Warangal

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Name: Middela Mounisai Siddartha Roll No: 141717 7. Priority rules: adoption of this concept from the PTV Vissim vehicle simulation allows for the simulation of specific situations, such as: 8. COM access 9. High time resolution: up to 10 simulation steps per seco nd 3.4 Applications

VISWALK can be effectively used in the following applications: 1. Space optimization and capacity planning

Simulate pedestrians behavior and design spaces in order to utilize them to the utmost extent. This includes for example shopping malls, stadiums etc. Evacuation analysis Plan secure ingress and egress flows and escape routes for example for train stations, airports, stadiums etc. 2. Plan and optimize mass attendee events

Develop proper crowd and site management strategies for high density events such as Olympic Games or other important sports events, concerts, festivals, etc. 3. Routing and queuing analysis

Shorten queuing times and guide pedestrians via alternative routes. 4. Assessment of alternatives

Compare costs and efforts of alternative planning and easily demonstrate the results. 5. Dwell time analysis

Establish boarding and alighting times for public means of transport and use VISSIM to simulate a complete operation of a rail or metro network.


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Name: Middela Mounisai Siddartha Roll No: 141717 3.5 Benefits 1. Scientific approach

Use simulation software based on latest scientific insights and validated against empirical measurements. 2. High levels of demand

Accommodate an extensive population density of more than 100,000 in a single simulation. 3. Efficiency

Reduce costs and project times by concurrently building your 2D and 3D models directly in VISWALK. 4. Usability

Start immediately your work and concentrate on your project, thanks to easy handling and comprehensive functionality of VISWALK. 5. Visualisation

Simulate 2D and 3D output with just a click of a button. 3.6 Differences between Pedestrian and Traffic Simulations

In many ways pedestrian flow are similar to those used for vehicular flow because it can be described in terms of familiar variables such as speed, v olume, rate of flow and density. Other measures related specifically to pedestrian flow include the ability to cross a pedestrian traffic stream, to walk in the reverse direction of a major pedestrian flow, to manoeuvre generally without conflicts and changes in walking speed, and the delay experienced by pedestrians at signalized and unsignalized intersections. It is dissimilar to the vehicular flow in that pedestrian flow may be unidirectional, bidirectional, or multi-directional. Pedestrian do not always travel in clear ”lanes” although they may do sometimes under heavy flow.


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Name: Middela Mounisai Siddartha Roll No: 141717 Vehicular simulation

1. The size of vehicle is large 2. Movement of vehicle is unidirectional 3. Speed of vehicle is high 4. it is comparably less depend upon psychological behavior of human here vehicle power is also considerable 5. Here density comes into picture

Pedestrian simulation

1. The size of pedestrian is less 2. Movement of pedestrian is multidirectional 3. Speed of pedestrian is considerably low 4. It depends upon psychological behavior of human 5. Here space comes into picture

3.6.1 Fundamental Relationships of Pedestrian Flow

The fundamental relationship between speed, density, and volume for pedestrian flow is analogous to vehicular flow. As volume and density increase, pedestrian speed declines. As density increases and pedestrian space decreases, the degree of mobility afforded to the individual pedestrian declines, as does the average speed of the pedestrian stream

Fig 3. Relationship between pedestrian speed and density


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Name: Middela Mounisai Siddartha Roll No: 141717 Flow-Density Relationships The relationship among density, speed, and flow for pedestrians is similar to that for vehicular traffic streams, and is expressed in equation. Q ped = S ped ∗ D ped where, Q ped = unit flow rate (p/min/m), S ped = pedestrian speed (m/min), and 2

D ped = pedestrian density (p/m ). Pedestrian density is an awkward variable in that it has fractional values in pedestrian per square meter. This relationship often expressed in terms of Space module (M) which is the inverse of pedestrian density. The inverse of density is more practical unit for analyzing pedestrian facilities ,so expression becomes Q ped = S ped / M 2

where M in(m /ped).

Fig 4. Relationship between pedestrian space & flow


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Fig 5. Relationships between Pedestrian Speed and Flow

Fig 6. Relationships between Pedestrian Speed and Space


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Name: Middela Mounisai Siddartha Roll No: 141717 3.6.2 Fundamental Relations of traffic flow:

Fig 7. Fundamental Relations of Traffic Flow

3.7 Case Study 3.7.1 Project: Pedestrian Footbridge Analysis for a Stadium. 3.7.2 Location : Perth, Australia 3.7.3 Overview: Perth is in the process of planning for a new 60,000 seat sporting stadium to be

located on the Burswood Peninsula. As a part of meeting the necessary mode share targets for this facility and ensuring a safe and comfortable pedestrian environment two major pedestrian footbridges are being planned and delivered. 1. A 575m long 10 m wide structure on the western side linking the peninsula over the swan river to the East Perth designed to process 12,500 people.


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Name: Middela Mounisai Siddartha Roll No: 141717 2. A 230 m long 15.3 m wide structure on the eastern side linking the facility with the car park designed to process 14,000 people. 3.7.4 Study:

Urbsol (Urban Solutions Private Limited) was engaged by the public transport authority (PTA) through BG&E to undertake a pedestrian capacity analysis of the two key pedestrian footbridges to ensure their operation would remain within the acceptable levels of service during peak loading or unloading times.

Fig 8. Pedestrian simulation in VISWALK

The peak loading or unloading times scenario meant that unidirectional pedestrian simulation needed to be applied on both footbridges. Due to length of the first bridge and slow speed of pedestrians coupled with crowding the pedestrian density increases and converges towards the end of simulation. The true footbridge capacity within acceptable level of service and the time required to discharge the target number of spectators was tested under these dynamic conditions.


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Fig 9. Example of pedestrian density on footbridge. 3.7.5 Simulation:

Urbsol used VISWALK pedestrian simulation software to access the pedestrian performance and the throughput of the two structures; The simulation based approach allowed for the true system dynamic to be accounted for and considered the following parameters: 1. Densities 2. Speeds 3. Travel times As part of simulation a sensitivity analysis was carried out where the effects of increasing the footbridge width in one scenario and installing seating benches (obstacles) along the walkway in another were tested. Due to dynamic nature of pedestrian crowding phenomenon the simulation outputs were aggregated in five minute intervals for plotting and subsequent analysis.


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Fig 10. Fruin LOS – Footbridge 1 Example output

VISWALK was chosen as the most suitable tool for this work for a number of reasons: 1. Well developed pedestrian algorithms derived from the social force model. 2. Fruin level of service reporting based on density. 3. Robust data collection and extraction. The project proposed that the proposed designs of both the Footbridges would operate within acceptable limits during peak times.


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Name: Middela Mounisai Siddartha Roll No: 141717 3.8 Lab Simulation

Fig 11. Creating Areas, Obstacles and Ramps/Stairs

Fig 12. Assigning Pedestrian Inputs


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Fig 13. Assigning Pedestrian Routes

Fig 14. Pedestrian Simulation


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Name: Middela Mounisai Siddartha Roll No: 141717 3.9 Result

Simulation has been done using VISWALK for an assumed location. 3.10 Conclusion

VISWALK is a very useful tool that makes the complex phenomenon of pedestrian modeling easier by simulation and required output from simulation. It helps to understand the actual phenomenon that may happen in the field. 3.11 References

1. Cecilia Friis, Lina Svensson, Pedestrian Microsimulation - A comparative study between the software programs Vissim and Viswalk, Department of Civil and Environmental Engineering,

Division of GeoEngineering, Road and Traffic Research Group, Chalmers

University of Technology. 2. Case study project on Pedestrian Footbridge Analysis, Urbsol, Perth, Australia. 3. Dr. Tom V. Mathew, Chapter 47, Pedestrian Studies, Transportation Systems Engineering, IIT Bombay. 4. http://vision-traffic.ptvgroup.com/en-uk/products/ptv-viswalk/ 5. http://www.traffic-inside.com/tag/pedestrian-simulation/


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Pedestrian simulation using Viswalk

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